报告题目：The Global Star Formation Laws in Star-forming Galaxies

报 告 人：高煜，Purple Mountain Observatory

报告时间：12月17日下午2：00

报告地点：蒙民伟科技南楼S727

报告摘要：The global star formation (SF) laws — the relations between star-forming gas and SF rate (SFR) — are reexamined in a large sample of 181 local star-forming galaxies with infrared luminosities (SFR) spanning almost five orders of magnitude. The surface density of dense molecular gas (as traced by HCN) has the tightest and linear correlation with that of SFR (ΣSFR). The ΣSFR is a steeper function of the total (H2+HI) Σgas than that of molecular gas ΣH2. We further show that the SFR and a variety of dense gas tracers (e.g., HCN, CS, their high-J and high-J CO) are all linearly correlated for both the Galactic dense cores and star-forming galaxies near and far. This has immediate implications on the modes of SF in galaxies because the dense cores are the sites of active SF, and thus the basic units in contributing to SF. The SFR should depend linearly upon the mass of dense molecular gas (the SF law!). These ground-based observations of last decade and recent Herschel results highlight what the ALMA is delivering on the studies of "SF laws" across large redshift ranges over wide SF scales.